1896; Union Oil Co., (On Review), 25 L. D. 351, decided November 6, 1897. It was in order to obviate the effect of the former of these two decisions that Congress passed the Act of February 11, 1897, c. 216, 29 Stat. 526, which declared: "That any person authorized to enter lands under the mining laws of the United States may enter and obtain patent to lands containing petroleum or other mineral oils, and chiefly valuable therefor, under the provisions of the laws relating to placer mineral claims"; with a proviso saving petroleum land theretofore filed upon, claimed or improved as mineral but not yet patented. See House Rep. No. 2655, 54th Cong., 2d sess.; 29 Cong. Rec., Pt. 2, p. 1409; Burke v. Southern Pacific R. R. Co., 234 U. S. 669, 678.

Aside from the suggested effect of the Act of 1903, it is clear that in order to create valid rights or initiate a title as against the United States a discovery of mineral is essential. Section 2320, Rev. Stats.; Waskey v. Hammer, 223 U. S. 85, 90. Nevertheless, § 2319 extends an express invitation to all qualified persons to explore the lands of the United States for valuable mineral deposits, and this and the following sections hold out to one who succeeds in making discovery the promise of a full reward. Those who, being qualified, proceed in good faith to make such explorations and enter peaceably upon vacant lands of the United States for that purpose are not treated as mere trespassers, but as licensees or tenants at will. For since, as a practical matter, exploration must precede the discovery of minerals, and some occupation of the land ordinarily is necessary for adequate and systematic exploration, legal recognition of the pedis possessio of a bona fide and qualified prospector is universally regarded as a necessity. It is held that upon the public domain a miner may hold the place in which he may be working against all others having no better right, and while he remains in possession, diligently working towards discov

ery, is entitled-at least for a reasonable time-to be protected against forcible, fraudulent, and clandestine intrusions upon his possession. Zollars v. Evans, 5 Fed. Rep. 172, 173; Crossman v. Pendery, 8 Fed. Rep. 693, 694; Johanson v. White, 160 Fed. Rep. 901; Hanson v. Craig, 161 Fed. Rep. 861, 863; 170 Fed. Rep. 62, 65; Gemmell v. Swain, 28 Montana, 331, 335; New England &c. Oil Co. v. Congdon, 152 California, 211; Whiting v. Straup, 17 Wyoming, 1, 19, 23; Phillips v. Brill, 17 Wyoming, 26, 38.1

And it has come to be generally recognized that while discovery is the indispensable fact and the marking and recording of the claim dependent upon it, yet the order of time in which these acts occur is not essential in the acquisition from the United States of the exclusive right of possession of the discovered minerals or the obtaining of a patent therefor, but that discovery may follow after location and give validity to the claim as of the time of discovery, provided no rights of third parties have intervened. Creede & Cripple Creek Mining Co. v. Uinta Tunnel Mining Co., 196 U. S. 337, 345, 348-352; Weed v. Snook, 144 California 439, 443.

In the California courts the right of a locator before discovery while in possession of his claim and prosecuting exploration work is recognized as a substantial interest, extending not only as far as the pedis possessio but to the limits of the claim as located; so that if a duly qualified person peaceably and in good faith enters upon vacant lands of the United States prior to discovery but for the purpose of discovering oil or other valuable mineral deposits, there being no valid mineral location upon it, such person has the right to maintain possession as against

Two recent acts of Congress contain recognition of the status of a bona fide occupant of oil-bearing lands in the public domain prior to discovery. Act of June 25, 1910 (36 Stat. 847, c. 421, § 2, first proviso); Act of March 2, 1911 (36 Stat. 1015, c. 201). See Consolidated Mutual Oil Co. v. United States. 245 Fed. Rep. 521, 524, 527, 529.

violent, fraudulent, and surreptitious intrusions so long as he continues to occupy the land to the exclusion of others and diligently and in good faith prosecutes the work of endeavoring to discover mineral thereon. Miller v. Chrisman, 140 California, 440, 447 (case affirmed 197 U. S. 313); Weed v. Snook, ubi supra; Merced Oil Mining Co. v. Patterson, 153 California, 624, 625; 162 California, 358, 361; McLemore v. Express Oil Co., 158 California, 559, 562.

To what extent the possessory right of an explorer before discovery is to be deduced from the invitation extended in § 2319, to what extent it is to be regarded as a local regulation of the kind recognized by that section and the following ones, and to what extent it derives force from the authority of the mining States to regulate the possession of the public lands in the interest of peace and good order, are questions with which we are not now concerned. Nor need we stop to inquire whether the right is limited to the ground actually occupied in the process of exploration, or extends to the limits of the claim. These questions and others that suggest themselves are not raised by the present record, which concerns itself solely with the rights asserted by the defendant under the Act of 1903. Whatever the nature and extent of a possessory right before discovery, all authorities agree that such possession may be maintained only by continued actual occupancy by a qualified locator or his representatives engaged in persistent and diligent prosecution of work looking to the discovery of mineral.

But, by the provisions of the Revised Statutes above cited, a discovery of mineral by a qualified locator upon unappropriated public land initiates rights much more substantial as against the United States and all the world. If he locates, marks, and records his claim in accordance with § 2324 and the pertinent local laws and regulations, he has, by the terms of § 2322, an exclusive right of pos

session to the extent of his claim as located, with the right to extract the minerals, even to exhaustion, without paying any royalty to the United States as owner, and without ever applying for a patent or seeking to obtain title to the fee; subject, however, to the performance of the annual labor specified in § 2324, for upon his failure to do this the claim is open to relocation by others at any time before resumption of work upon it by the original locator.

If not content to rest upon the right conferred by § 2322, the qualified locator may obtain a patent for his claim by complying with the conditions prescribed by §§ 2325 and 2326.

But, even without patent, the possessory right of a qualified locator after discovery of minerals upon the claim is a property right in the full sense, unaffected by the fact that the paramount title to the land is in the United States (Rev. Stats., § 910), and it is capable of transfer by conveyance, inheritance, or devise. Forbes v. Gracey, 94 U. S. 762, 763, 767; Belk v. Meagher, 104 U. S. 279, 283, 285; Del Monte Mining Co. v. Last Chance Mining Co., 171 U. S. 55, 78; Elder v. Wood, 208 U. S. 226, 232.

Actual and continuous occupation of a valid mining location based upon discovery is not essential to the preservation of the possessory right. The right is lost only by abandonment, as by non-performance of the annual labor required by § 2324. Belk v. Meagher, 104 U. S. 279, 283, 284; Black v. Elkhorn Mining Co., 163 U. S. 445, 450; Farrell v. Lockhart, 210 U. S. 142, 147; Bradford v. Morrison, 212 U. S. 389, 394.

After this brief review of the mining laws there is little danger of mistaking the true intent and meaning of the Act of Congress of February 12, 1903. Title thirty-two, chapter six, Revised Statutes, therein referred to, embraces the sections we have cited. And

it is not to be doubted that the terms "assessments" and "annual assessment labor" refer to the annual labor required by § 2324, that being commonly called by miners the "annual assessment" or the "assessment work," and so described in many judicial opinions and in at least two acts of Congress, passed respectively November 3, 1893, c. 12, 28 Stat. 6, and July 2, 1898, c. 563, 30 Stat. 651. See El Paso Brick Co. v. McKnight, 233 U. S. 250, 255, 256, 258.

And it is important to observe that in these acts of Congress, as in the practice of miners, "assessment work" had nothing to do with locating or holding a claim before discovery. On the contrary it was the condition subsequent prescribed by Congress to be performed in order to preserve the exclusive right to the possession of a valid mineral land location upon which discovery had been made. McLemore v. Express Oil Co., 158 California, 559, 563. Hence the declaration in the Act of 1903 that where oil lands are located as placer mining claims "the annual assessment labor upon such claims may be done upon any one of a group of claims lying contiguous and owned by the same person," indicates simply the legislative purpose that the necessary assessment work if done upon one of the group should have the same effect as if properly distributed among the several claims; that is to say, the effect of preserving the exclusive right of possession and enjoyment conferred by § 2322 with respect to unpatented claims based upon a previous discovery of oil.

"Group assessment work" did not originate with the Act of 1903. From an early period the economy of operating contiguous mines or claims by a single system was recognized. In § 5 of the Act of May 10, 1872, c. 152, 17 Stat. 92, now § 2324, Rev. Stats., it was provided with respect to the annual labor that "where such claims are held in common such expenditure may be made upon any one claim." Questions as to the precise meaning of